/*
 * YAJHFC - Yet another Java Hylafax client
 * Copyright (C) 2005-2011 Jonas Wolz <info@yajhfc.de>
 *
 *  This program is free software: you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation, either version 3 of the License, or
 *  (at your option) any later version.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program.  If not, see <http://www.gnu.org/licenses/>.
 *
 *  Linking YajHFC statically or dynamically with other modules is making 
 *  a combined work based on YajHFC. Thus, the terms and conditions of 
 *  the GNU General Public License cover the whole combination.
 *  In addition, as a special exception, the copyright holders of YajHFC 
 *  give you permission to combine YajHFC with modules that are loaded using
 *  the YajHFC plugin interface as long as such plugins do not attempt to
 *  change the application's name (for example they may not change the main window title bar 
 *  and may not replace or change the About dialog).
 *  You may copy and distribute such a system following the terms of the
 *  GNU GPL for YajHFC and the licenses of the other code concerned,
 *  provided that you include the source code of that other code when 
 *  and as the GNU GPL requires distribution of source code.
 *  
 *  Note that people who make modified versions of YajHFC are not obligated to grant 
 *  this special exception for their modified versions; it is their choice whether to do so.
 *  The GNU General Public License gives permission to release a modified 
 *  version without this exception; this exception also makes it possible 
 *  to release a modified version which carries forward this exception.
 */
package yajhfc.file;

import java.util.ArrayList;
import java.util.Collections;
import java.util.EnumMap;
import java.util.List;
import java.util.Map;

import javax.swing.filechooser.FileFilter;

/**
 * @author jonas
 *
 */
public final class FileConverters {
    private static final List<FileConverterSource> sources = new ArrayList<FileConverterSource>();
    static {
        addFileConverterSource(new DefaultConvertersSource());
        addFileConverterSource(new UserDefinedConvertersSource());
    }
    private static Map<FileFormat,FileConverter> fileConverters = null;
    private static FileFilter[] acceptedFilters;

    
    public synchronized static void addFileConverterSource(FileConverterSource source) {
        sources.add(source);
        invalidateFileConverters();
    }
    
    public synchronized static void removeFileConverterSource(FileConverterSource source) {
        sources.remove(source);
        invalidateFileConverters();
    }
    
    /**
     * Called to notify this class that the file converter map may have changed and
     * any information computed from that map should be refreshed
     */
    public static void invalidateFileConverters() {
        fileConverters = null;
        acceptedFilters = null;
    }

    /**
     * Returns a file converter for the given file format
     * 
     * @param format
     * @return
     */
    public static FileConverter getConverterFor(FileFormat format) {
        return getFileConverters().get(format);
    }
    
    /**
     * Returns a map mapping file converters to a given file format.
     * 
     * @param format
     * @return
     */
    public synchronized static Map<FileFormat, FileConverter> getFileConverters() {
        if (fileConverters == null) {
            Map<FileFormat,FileConverter> converterMap = new EnumMap<FileFormat, FileConverter>(FileFormat.class);
            Collections.sort(sources);
            for (FileConverterSource src : sources) {
                src.addFileConvertersTo(converterMap);
            }
            fileConverters = Collections.unmodifiableMap(converterMap);
        }
        return fileConverters;
    }
    
    public static FileFilter[] getConvertableFileFilters() {
        if (acceptedFilters == null) {
            acceptedFilters = FileFormat.createFileFiltersFromFormats(getFileConverters().keySet());
        }
        return acceptedFilters;
    }
    
}
